cl::desc("Wrap indirect calls with a given function"),
cl::Hidden);
+static cl::opt<bool> ClWrapIndirectCallsFast("msan-wrap-indirect-calls-fast",
+ cl::desc("Do not wrap indirect calls with target in the same module"),
+ cl::Hidden, cl::init(true));
+
namespace {
/// \brief An instrumentation pass implementing detection of uninitialized
/// function.
GlobalVariable *OriginTLS;
+ GlobalVariable *MsandrModuleStart;
+ GlobalVariable *MsandrModuleEnd;
+
/// \brief The run-time callback to print a warning.
Value *WarningFn;
/// \brief Run-time helper that copies origin info for a memory range.
IndirectCallWrapperFn = M.getOrInsertFunction(
ClWrapIndirectCalls, AnyFunctionPtrTy, AnyFunctionPtrTy, NULL);
}
+
+ if (ClWrapIndirectCallsFast) {
+ MsandrModuleStart = new GlobalVariable(
+ M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
+ 0, "__executable_start");
+ MsandrModuleStart->setVisibility(GlobalVariable::HiddenVisibility);
+ MsandrModuleEnd = new GlobalVariable(
+ M, IRB.getInt32Ty(), false, GlobalValue::ExternalLinkage,
+ 0, "_end");
+ MsandrModuleEnd->setVisibility(GlobalVariable::HiddenVisibility);
+ }
}
/// \brief Module-level initialization.
};
SmallVector<ShadowOriginAndInsertPoint, 16> InstrumentationList;
SmallVector<Instruction*, 16> StoreList;
+ SmallVector<CallSite, 16> IndirectCallList;
MemorySanitizerVisitor(Function &F, MemorySanitizer &MS)
: F(F), MS(MS), VAHelper(CreateVarArgHelper(F, MS, *this)) {
DEBUG(dbgs() << "DONE:\n" << F);
}
+ void materializeIndirectCalls() {
+ for (size_t i = 0, n = IndirectCallList.size(); i < n; i++) {
+ CallSite CS = IndirectCallList[i];
+ Instruction *I = CS.getInstruction();
+ BasicBlock *B = I->getParent();
+ IRBuilder<> IRB(I);
+ Value *Fn0 = CS.getCalledValue();
+ Value *Fn = IRB.CreateBitCast(Fn0, MS.AnyFunctionPtrTy);
+
+ if (ClWrapIndirectCallsFast) {
+ // Check that call target is inside this module limits.
+ Value *Start =
+ IRB.CreateBitCast(MS.MsandrModuleStart, MS.AnyFunctionPtrTy);
+ Value *End = IRB.CreateBitCast(MS.MsandrModuleEnd, MS.AnyFunctionPtrTy);
+
+ Value *NotInThisModule = IRB.CreateOr(IRB.CreateICmpULT(Fn, Start),
+ IRB.CreateICmpUGE(Fn, End));
+
+ PHINode *NewFnPhi =
+ IRB.CreatePHI(Fn0->getType(), 2, "msandr.indirect_target");
+
+ Instruction *CheckTerm = SplitBlockAndInsertIfThen(
+ cast<Instruction>(NotInThisModule),
+ /* Unreachable */ false, MS.ColdCallWeights);
+
+ IRB.SetInsertPoint(CheckTerm);
+ // Slow path: call wrapper function to possibly transform the call
+ // target.
+ Value *NewFn = IRB.CreateBitCast(
+ IRB.CreateCall(MS.IndirectCallWrapperFn, Fn), Fn0->getType());
+
+ NewFnPhi->addIncoming(Fn0, B);
+ NewFnPhi->addIncoming(NewFn, dyn_cast<Instruction>(NewFn)->getParent());
+ CS.setCalledFunction(NewFnPhi);
+ } else {
+ Value *NewFn = IRB.CreateBitCast(
+ IRB.CreateCall(MS.IndirectCallWrapperFn, Fn), Fn0->getType());
+ CS.setCalledFunction(NewFn);
+ }
+ }
+ }
+
/// \brief Add MemorySanitizer instrumentation to a function.
bool runOnFunction() {
MS.initializeCallbacks(*F.getParent());
// Insert shadow value checks.
materializeChecks();
+ // Wrap indirect calls.
+ materializeIndirectCalls();
+
return true;
}
/// \brief Cast between two shadow types, extending or truncating as
/// necessary.
- Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy) {
+ Value *CreateShadowCast(IRBuilder<> &IRB, Value *V, Type *dstTy,
+ bool Signed = false) {
Type *srcTy = V->getType();
if (dstTy->isIntegerTy() && srcTy->isIntegerTy())
- return IRB.CreateIntCast(V, dstTy, true);
+ return IRB.CreateIntCast(V, dstTy, Signed);
if (dstTy->isVectorTy() && srcTy->isVectorTy() &&
dstTy->getVectorNumElements() == srcTy->getVectorNumElements())
- return IRB.CreateIntCast(V, dstTy, true);
+ return IRB.CreateIntCast(V, dstTy, Signed);
size_t srcSizeInBits = VectorOrPrimitiveTypeSizeInBits(srcTy);
size_t dstSizeInBits = VectorOrPrimitiveTypeSizeInBits(dstTy);
Value *V1 = IRB.CreateBitCast(V, Type::getIntNTy(*MS.C, srcSizeInBits));
Value *V2 =
- IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), true);
+ IRB.CreateIntCast(V1, Type::getIntNTy(*MS.C, dstSizeInBits), Signed);
return IRB.CreateBitCast(V2, dstTy);
// TODO: handle struct types.
}
}
}
- // Replace call to (*Fn) with a call to (*IndirectCallWrapperFn(Fn)).
- void wrapIndirectCall(IRBuilder<> &IRB, CallSite CS) {
- Value *Fn = CS.getCalledValue();
- Value *NewFn = IRB.CreateBitCast(
- IRB.CreateCall(MS.IndirectCallWrapperFn,
- IRB.CreateBitCast(Fn, MS.AnyFunctionPtrTy)),
- Fn->getType());
- setShadow(NewFn, getShadow(Fn));
- CS.setCalledFunction(NewFn);
- }
-
void visitCallSite(CallSite CS) {
Instruction &I = *CS.getInstruction();
assert((CS.isCall() || CS.isInvoke()) && "Unknown type of CallSite");
IRBuilder<> IRB(&I);
if (MS.WrapIndirectCalls && !CS.getCalledFunction())
- wrapIndirectCall(IRB, CS);
+ IndirectCallList.push_back(CS);
unsigned ArgOffset = 0;
DEBUG(dbgs() << " CallSite: " << I << "\n");
"_msprop_select_agg");
} else {
// Sa = (sext Sb) | (select b, Sc, Sd)
- S = IRB.CreateOr(
- S, CreateShadowCast(IRB, getShadow(I.getCondition()), S->getType()),
- "_msprop_select");
+ S = IRB.CreateOr(S, CreateShadowCast(IRB, getShadow(I.getCondition()),
+ S->getType(), true),
+ "_msprop_select");
}
setShadow(&I, S);
if (MS.TrackOrigins) {
Value *ResShadow = IRB.CreateExtractValue(AggShadow, I.getIndices());
DEBUG(dbgs() << " ResShadow: " << *ResShadow << "\n");
setShadow(&I, ResShadow);
- setOrigin(&I, getCleanOrigin());
+ setOriginForNaryOp(I);
}
void visitInsertValueInst(InsertValueInst &I) {
Value *Res = IRB.CreateInsertValue(AggShadow, InsShadow, I.getIndices());
DEBUG(dbgs() << " Res: " << *Res << "\n");
setShadow(&I, Res);
- setOrigin(&I, getCleanOrigin());
+ setOriginForNaryOp(I);
}
void dumpInst(Instruction &I) {